Previously, I wrote about the use of neuroscience in the courtroom as a defense for criminal actions. I asserted that these arguments hold water only insofar as they can demonstrate a clear causal connection between the brain injury and the criminal behavior, and that it was not possible for the defendant to control himself in the presence of such a brain injury.

Although I am a card-carrying pinko, I am enjoying the new book by Gene Heyman, Addiction: A Disorder of Choice. (A longer review post forthcoming once I finish the book). Heyman challenges the view that addiction is a compulsory chronic and relapsing condition. By illustrating historical, cultural and individual differences in drug reactions, he shows that drug dependence can be overcome with will (and massive amounts of effort and motivation). This brings us right back to the question we left off with last time: under what circumstances can we reasonably expect a person to demonstrate self-control?

A common model of self-control posits that exhibiting self-control is an effortful, resource-consuming process. According to this model, a person has a set amount of self-control that can be exhibited before failure and/or “recharge”. A common source of evidence for this model is the fact that exhibiting self-control appears to consume a good deal of glucose. (Of course, this is a very interesting idea for those whose self-control is being directed towards dieting!) Another measure of self-control failure are mistakes on a Stroop test.

A compelling new study examines the limitations of the resource-limitation model of self-control. A first experiment demonstrated that people who do not agree with the resource-limitation model made fewer mistakes on the Stroop test following a cognitively demanding task than did those who professed beliefs in the model. Even stronger was a second experiment where manipulation of participants’ beliefs in the model had the same effects. Of course, like many things in psychology, William James was here before us when he stated “The greatest discovery of my generation is that a human being can alter his life by altering his attitudes”.